(3

Canary Grass glass strips Jan 5. 1878

fastened on with shellac

Glass Splinter

(7) .25 long plant .55 inch high

(8) .15 plant .30

9 .28 abt plant .7 high bowed away from [sketch] 9

10. .26 abt plant .6.0 high.

Put the lamp so that they ought to bend with glass on convex side.—

(9) now points rather at rt angle to light-line — the others slope away. — 5 or 10 minutes it was turned round so that 6, 7, 8, pointed a little to light. 5. 15 P.m

7. Very slightly more bent than it was—

8 bent much & low down.

9 bent towards light slightly ∴ has moved fairly

10 bent a little. But 9 & 10 & certainly not nearly bent so much as 3 neighbours

8° 30 P.m

(7) nearly as much bowed as plant beyond it

(8) as much bowed as any

(9) slightly bowed — glass separated

(10) slightly bowed like (9) glass separated

on Two of the free plants not more bowed than those with glass

Next morning Jan 6th. 8° a.m. All 4 with glass splinters quite vertical; whereas most of others still inclined considerably to light. I noticed last night at 10° 30' P.m. that the seedlings with splinters were nearly upright— clearly checks action.

[77v]

[calculations]

[78]

Phalaris canariensis Caps of Quills not painted

Jan 5. (78)

Caps were made of the tubes from small dark feathers; & were put on at about 10. A.M. 9' P.m— removed. exposed before Candle in dark-room.

No. 1 cap .4" inch long. slightly curved towards light in the cap, & a good deal bent near ground. altogether distinctly pointing to the light. total length 1" inch

No. 2. Cap .3" long. Quite straight in cap. pointing very decidedly to the light. total length 1.5"

No. 3 Cap .3" long. Very much curved to light in the cap, otherwise quite vertical Total length .7"

No. 4. Cap .3" long. Slightly curved in cap otherwise vertical. total length 1.5"

No. 5. Top was injured i.e blade was growing out of sheath & so goes for nothing

Too old—

All the caps were too big

Shows light acts through quills—

Horace Darwin